The document NCERT Solutions(Part - 1) - Symmetry Class 7 Notes | EduRev is a part of the Class 7 Course Mathematics (Maths) Class 7.

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**Exercise 14.1 **

**Question 1: **

**Copy the figures with punched holes and find the axes of symmetry for the following: **

**Answer 1: **

S. No. | Punched holed figures | The axes of symmetry |

(a) | ||

(b) | ||

(c) | ||

(d) | ||

(e) | ||

(f) | ||

(g) | ||

(i) | ||

(j) | ||

(k) | ||

(l) |

**Question 2: **

**Express the following in exponential form: **

**Answer 2: **

S. No. | Line(s) of symmetry | Other holes on figures |

(a) | ||

(b) | ||

(c) | ||

(d) | ||

(e) |

**Question 3: **

**In the following figures, the mirror line (i.e., the line of symmetry) is given as a dotted line. Complete each figure performing reflection in the dotted (mirror) line. (You might perhaps place a mirror along the dotted line and look into the mirror for the image). Are you able to recall the name of the figure you complete?**

**Answer 3: **

S.No. | Question figures | Complete figures | Names of the figure |

(a) | Square | ||

(b) | Triangle | ||

(c) | Rhombus | ||

(d) | Circle | ||

(e) | Pentagon | ||

(f) | Octagon |

**Question 4: **

**The following figures have more than one line of symmetry. Such figures are said to have multiple lines of symmetry: **

Identify multiple lines of symmetry, if any, in each of the following figures:

**Answer 4: **

S.No. | Problem Figures | Lines of symmetry |

(a) | ||

(b) | ||

(c) | ||

(d) | ||

(e) | ||

(f) | ||

(g) | ||

(h) |

**Question 5: **

**Copy the figure given here: **

**Take any one diagonal as a line of symmetry and shade a few more squares to make the figure symmetric about a diagonal. Is there more than one way to do that? Will the figure be symmetric about both the diagonals? **

**Answer 5: **

Answer figures are:

Yes, there is more than one way. Yes, this figure will be symmetric about both the diagonals.

**Question 6: **

**Copy the diagram and complete each shape to be symmetric about the mirror line(s): **

**Answer 6: **

**Question 7: **

**State the number of lines of symmetry for the following figures: **

**(a) An equilateral triangle **

**(b) An isosceles triangle **

**(c) A scalene triangle **

**(d) A square **

**(e) A rectangle **

**(f) A rhombus **

**(g) A parallelogram **

**(h) A quadrilateral **

**(i) A regular hexagon **

**(j) A circle **

**Answer 7: **

S.No. | Figure’s name | Diagram with symmetry | Number of lines |

(a) | Equilateral triangle | 3 | |

(b) | Isosceles triangle | 1 | |

(c) | Scalene triangle | 0 | |

(d) | Square | 4 | |

(e) | Rectangle | 2 | |

(f) | Rhombus | 2 | |

(g) | Parallelogram | 0 | |

(h) | Quadrilateral | 0 | |

(i) | Regular Hexagon | 6 | |

(j) | Circle | Infinite |

**Question 8: **

**What letters of the English alphabet have reflectional symmetry (i.e., symmetry related to mirror reflection) about. **

**(a) a vertical mirror **

**(b) a horizontal mirror **

**(c) both horizontal and vertical mirrors **

**Answer 8: **

**(a) Vertical mirror - A, H, I, M, 0, T, U, V, W, X and Y**

(b) Horizontal mirror - B, C, D, E, H, I, 0 and X

**Question 9: **

**Give three examples of shapes with no line of symmetry. **

**Answer 9: **

The three examples are:

1. Quadrilateral

2. Scalene triangle

3. Parallelogram

**Question 10: **

**What other name can you give to the line of symmetry of: **

**(a) an isosceles triangle? **

**(b) a circle? **

**Answer 10: **

(a) The line of symmetry of an isosceles triangle is median or altitude.

(b) The line of symmetry of a circle is diameter.

**Exercise 14.2 **

**Question 1: Which of the following figures have rotational symmetry of order more than 1: **

**Answer 1: **

Rotational symmetry of order more than 1 are (a),(b),(d),(e) and (f) because in these figures, a complete turn, more than 1 number of times, an object looks exactly the same.

**Question 2: **

**Give the order the rotational symmetry for each figure: **

**Answer 2: **

S.No. | Problem figures | Rotational figures | Order of rotational symmetry |

(a) | 2 | ||

(b) | 2 | ||

(c) | 3 | ||

(d) | 4 | ||

(e) | 4 | ||

(f) | 5 | ||

(g) | 6 | ||

(h) | 3 |

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